2003 PLC doesn't start due to failure of power supply

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1

Hello colleagues.

I have two B&R PLCs installed on two presses, but the following problem occurs randomly from time to time.

I turn on the panel, but the B&R 2003 PLC does not turn on. After turning on the panel, I measured the voltage at the CPU input (power supply: +24 VDC) and it was 24 V, without variations, but the PLC still does not turn on.

The PLC only turns on after blow hot air on the area highlighted in the image (one or two minutes later).

I noticed that this event occurs mainly on cold days.

Has this situation ever happened to any of you?

I believe it is an internal problem in the CPU power supply, which prevents it from starting, involving some thermal component (such as PTC or NTC, where the component reacts to the increase/decrease in temperature). However, I did not want to disassemble the power supply because I saw that it is integrated directly into the CPU (model 7CP476-60.1).

Any help is welcome.

Thanks.

Image - Blowing hot air in power supply region
Image - Blowing hot air in power supply region561×604 35.8 KB

2

Hello,

It’s best if you replace the CPU. Since the controller is discontinued, I suggest replacing it with a currently available CPU. Your controller has a Motorola processor (SG3). Since B&R only uses Intel processors (SG4), you’ll need to adapt your software accordingly.

Regards
Stephan

3

I would agree with Stephan that there is a defect.

It sounds like an aged electrolytic capacitor in the switching power supply. If you heat them up, you get a little more capacity back for a short time.

You can try sending the control unit to B&R Austria for repair.

4

Hello colleagues,

Here’s an update on the CPU.

I have a B&R 2003 CPU, model 7CP476.60-1, which was returned from technical assistance after its power supply was repaired.

When I turn on the CPU with the CAN-ID Nr switches in the “0 1” position, the ERR, RDY, and RUN LEDs blink.

The RS232 LED blinks very faintly approximately every 5 seconds.

The problem is that I cannot communicate with it in any way to reprogram it.

From what little I’ve read in the B&R 2003 manual, there’s only one possibility where all three LEDs can function simultaneously, which is when the CPU enters “Service” mode.

I have the B&R PG2000 v2.41 software and the original source code from the machine where the CPU was installed. I use a laptop with a real RS-232 port with Windows XP installed, and to open the software I use a virtual machine with Windows 95.

- The port originally recognized by the system is COM1. In the communication parameters (driver settings), I chose 57600, 8, E, 1.

- I know the problem is not the cable, as I can communicate with other CPUs of the same model that are operating in the machines.

- I then thought about updating the CPU’s operating system (programming system flash). So, I set the CAN-ID Nr. keys to the “0 0” position.

  1. In settings > connections, I chose the option mo_p1n57.br, but the CPU does not establish communication with the laptop. Several times the message “Error 4920: Bootmanager - Connection Lost!” appeared.

  2. I tried the option target > service > update PCCSW. The laptop attempts to communicate with the CPU, resulting in the following window:

“Push the reset button on the…” (The window doesn’t enlarge, so I can’t see the complete message). Below this message, it shows the option to choose the Baud Rate (set to 57600) and the COM port (selected as COM1).

I click OK, and at the bottom, the message appears: “Connection is being established - please wait!”.

After a few moments, a window appears with the message “Error 4960: Bootmanager - No valid system file to select!”.

I also tried diagnosing the CPU (target > service > Diagnose) using the same communication parameters as before, but leaving the CAN-ID keys in the “F F” position, but I was unsuccessful.

I returned to the technical assistance where the CPU was repaired, and they said that the operating system has already been installed. They did this through a DOS program called BOOTCOMM v3.00 B&R. We tested it on their own laptop. I observed that the RS-232 LED blinks constantly, the program recognizes the communication between the laptop and the CPU, identifying the model (CP476), and starts downloading the operating system after erasing the Flash memory.

The program scans the entire memory and completes the recording 100% without errors.

Afterwards, I asked them to program the original source code of the machine using the same program, changing the CAN-ID keys to the “0 1” position, but they couldn’t because the COM port communication is not recognized under these conditions.

Is there a missing step when trying to establish communication? Is there anything else I can try using the B&R PG2000 software?

Any help is welcome.

Thanks.